In order to pass the U.S. Military ballistic impact resistance requirements, the Hellfly Sunglass must pass the stringent test protocol (MIL-PRF-31013, clause 3.5.1.1). This rigorous test subjects the Hellfly to a 0.15 caliber, 5.8 grain, T37 shaped projectile which impacts the eyewear at 640 to 660 feet per second. The Hellfly well exceeds the ballistic standard and the wrap-around design ensures that the wearer is fully protected against unexpected fragments and extreme conditions.